<!DOCTYPE html>
<html>
<head>
    <title>GH-770</title>
</head>
<body>
<div>
    <input id="input" value="Test">
</div>
<div id="forceInputFocusDiv" style="width:20px;height:20px; left:15px; top:15px; background: red"></div>
</div>
<div id="simpleDiv" style="width:20px;height:20px; left:15px; top:15px; background: green"></div>
<script>
    var input              = document.getElementById('input');
    var forceInputFocusDiv = document.getElementById('forceInputFocusDiv');

    forceInputFocusDiv.addEventListener('mousedown', function () {
        input.focus();
    });
</script>
</body>
</html>